Hydrocarbon pyrolysis using submicron-sized high entropy alloy catalyst for production of hydrogen

Abstract

High entropy alloy catalysts may be used for production of hydrogen. An example method of hydrogen production may include: introducing a hydrocarbon to a reactor, wherein the reactor contains therein a catalyst, wherein the reactor is substantially absent of oxygen and water, wherein the catalyst comprises a high entropy alloy and a catalyst support, wherein the catalyst is present in a form of a first plurality of particles, wherein the first plurality of particles is submicron-sized, wherein the high entropy alloy has an entropy, S, such that S≥ 12.47 J K −1 mol −1 , and wherein the high entropy alloy comprises at least five of: iron, cobalt, manganese, nickel, molybdenum, copper, zinc, titanium, chromium, vanadium, aluminum, gallium, ruthenium, rhodium, palladium, silver, indium, tungsten, rhenium, iridium, platinum, gold, and bismuth; and reacting the hydrocarbon over the catalyst to produce solid carbon and hydrogen gas.

What is claimed is: 
     
         1 . A method comprising:
 introducing a hydrocarbon to a reactor,
 wherein the reactor contains therein a catalyst, 
 wherein the reactor is substantially absent of oxygen and water, 
 wherein the catalyst comprises a high entropy alloy and a catalyst support, 
 wherein the catalyst is present in a form of a first plurality of particles, 
 wherein the first plurality of particles is submicron-sized, 
 wherein the high entropy alloy has an entropy, S, such that S≥12.47 J K −1  mol −1 , and 
 wherein the high entropy alloy comprises at least five of: iron, cobalt, manganese, nickel, molybdenum, copper, zinc, titanium, chromium, vanadium, aluminum, gallium, ruthenium, rhodium, palladium, silver, indium, tungsten, rhenium, iridium, platinum, gold, and bismuth; and 
   reacting the hydrocarbon over the catalyst to produce solid carbon and hydrogen gas.   
     
     
         2 . The method of  claim 1 , wherein each metal of the high entropy alloy has a composition in the high entropy alloy from 0.1 at % (atomic percentage) to 50 at %. 
     
     
         3 . The method of  claim 1 , wherein the catalyst is located in a fluidized bed within the reactor. 
     
     
         4 . The method of  claim 1 , further comprising:
 purging the reactor with an inert gas prior to introducing the hydrocarbon to remove the oxygen, the water, or a combination thereof.   
     
     
         5 . The method of  claim 4 , further comprising heating the reactor at least partially during purging of the reactor. 
     
     
         6 . The method of  claim 5 , wherein the reactor is heated by hydrocarbon heating, induction heating, plasma heating, microwave heating, solar furnace heating, radiative heating, or any combination thereof. 
     
     
         7 . The method of  claim 6 , wherein electrical energy for heating the reactor is sourced from a renewable generation source. 
     
     
         8 . The method of  claim 1 , further comprising collecting the solid carbon. 
     
     
         9 . The method of  claim 8 , wherein the collecting uses a cyclonic separator. 
     
     
         10 . The method of  claim 1 , further comprising separating the hydrogen gas from the solid carbon and remaining hydrocarbon. 
     
     
         11 . The method of  claim 10 , wherein the separating uses a separation membrane. 
     
     
         12 . The method of  claim 1 , wherein the high entropy alloy is present in a form of a second plurality of particles, wherein the second plurality of particles has an average dimension from 1 nm to 500 nm. 
     
     
         13 . The method of  claim 1 , wherein the first plurality of particles has an average dimension of catalyst from 0.2 μm to 5 μm. 
     
     
         14 . The method of  claim 1 , wherein the catalyst support comprises Al 2 O 3 , and wherein the high entropy alloy comprises FeCoMnNiCu, FeCoMnNiMo, or any combination thereof. 
     
     
         15 . The method of  claim 1 , wherein the high entropy alloy comprises iron, cobalt, manganese, nickel, and:
 a) molybdenum,   b) copper, or   c) molybdenum and copper; and   wherein the iron, the cobalt, the manganese, the nickel, and the molybdenum and/or the copper are in equimolar concentration.   
     
     
         16 . The method of  claim 1 , wherein a temperature of the reactor is from 300° C. to 1200° C. 
     
     
         17 . A method comprising:
 purging a reactor with an inert gas so as to remove oxygen, water, or a combination thereof, wherein the inert gas comprises nitrogen, argon, or any combination thereof;   introducing a hydrocarbon to the reactor,
 wherein the reactor contains therein a catalyst, 
 wherein the catalyst comprises a high entropy alloy and an aluminum-based catalyst support, 
 wherein the catalyst is present in a form of a first plurality of particles, 
 wherein the first plurality of particles is submicron-sized, 
 wherein the high entropy alloy has an entropy, S, such that S≥12.47 J K −1  mol −1 , and 
 wherein the high entropy alloy comprises at least five of: iron, cobalt, manganese, nickel, molybdenum, copper, zinc, titanium, chromium, vanadium, aluminum, gallium, ruthenium, rhodium, palladium, silver, indium, tungsten, rhenium, iridium, platinum, gold, and bismuth; and 
   reacting the hydrocarbon with the catalyst to produce solid carbon and produced gas,   wherein the produced gas comprises hydrogen gas.   
     
     
         18 . The method of  claim 17 , wherein the hydrocarbon comprises methane, ethane, propane, gasoline, kerosene, diesel fuel, residual oil, crude oil, or any combination thereof. 
     
     
         19 . A method comprising:
 introducing a hydrocarbon to a reactor,
 wherein the reactor contains therein a catalyst, 
 wherein the reactor is substantially absent of oxygen and water, 
 wherein the catalyst comprises a high entropy alloy and an aluminum-based catalyst support, 
 wherein the catalyst is present in a form of a first plurality of particles, 
 wherein the first plurality of particles is submicron-sized, 
 wherein the high entropy alloy has an entropy, S, such that S≥12.47 J K −1  mol −1 , and 
 wherein the high entropy alloy consists essentially of iron, cobalt, manganese, nickel, and
 a) molybdenum, 
 b) copper, or 
 c) molybdenum and copper; and 
 
   reacting the hydrocarbon over the catalyst to produce solid carbon and hydrogen gas.   
     
     
         20 . The method of  claim 19 , wherein the iron, the cobalt, the manganese, the nickel, and the molybdenum and/or the copper are in equimolar concentration.